Try elecampane tincture “This herb is commonly used to treat acute bronchitis, especially when one is coughing up large amounts of yellow-green phlegm, although this symptom should always be promptly investigated to determine if antibiotics are necessary,” Kalnins says. Research confi rms that elecampane root is signifi cantly antibacterial. BEST BUY Herb Pharm Elecampane ($12 and up; herb-pharm.com)